Rear Door Trim - 2 Sets of Holes ???

[CRW-FK5]

I am installing a set of interior stainless steel trim pieces in my 1970 Charger, as they were not there when I bought the car.  I recently picked up a set and when installing them I noticed on the rear interior frames there are actually 2 sets of slots for mounting these and only one front round hole.  I was just going to pick the set that matched the holes on the trim pieces but noticed that on the left side they line up with the upper set of slots and on the right side they line up with the lower set of slots (again, only one round hole at the front so slots do put trim on slight angle relative to each position).  I am confused as to 1) why there are 2 sets of slots and only a single round hole (not 2 sets of round holes), and 2) why the trim pieces match up with different sets from side to side.  

FYI - The door panel seems to fit only when trim is on upper set, so my plan is to drilling new holes on the RH trim piece, but can anyone explain why 2 sets of slots and is it this way on all B-bodies?

Pictures below show the issue with the RH side.  Second picture I am holding the trim piece up and out of the way so you can see the 2 sets of slots and how the trim piece only matches one.  Thanks.

[Brock Lee]

Yes, it is a part made to fit all 2 door B-bodies. One set of holes is for that trim. The other is for the non-padded cars which have a painted metal cover instead of a pad held on by clips.

Slotted holes allow for the tolerances in assembly. It gives the assembler plenty of room to adjust the final placement.

[CRW-FK5]

Yes, it is a part made to fit all 2 door B-bodies. One set of holes is for that trim. The other is for the non-padded cars which have a painted metal cover instead of a pad held on by clips.

Slotted holes allow for the tolerances in assembly. It gives the assembler plenty of room to adjust the final placement.

Thanks.  Yes I understand the use of 1 hole and the rest slots, but my point was why then wouldn't there be another front round hole just above (or below) the one that's there now, as this would complete a full second set.  Instead, there is only a single hole in front and 2 sets of slots behind it, creating a anglular difference with the trim piece depending on which set you use.  To make it more confusing, as I said, the trim piece matches up to one set of slots on the LH side (lower) but the other set on the RH side (upper).  That's what I'm trying to figure out.